Shaft mounted monitor for rotating machinery

• US 10,063,124 B2
• Filed: 12/07/2016
• Issued: 08/28/2018
• Est. Priority Date: 12/10/2015
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Donolo, Marcos A.
• Primary Examiner(s): DUDA, RINA I
• Application Number:
  US15/372,209
• Publication Number:
  US 20170170773A1
• Time in Patent Office: 629 Days
• Field of Search: 318432-434
• CPC Class Codes: G05B 19/4062 Monitoring servoloop, e.g. overload of servomotor, loss of feedback or reference
• CPC Class Codes: H02K 11/21 Devices for sensing speed or position, or actuated thereby specially adapted for machines having non-mechanical commutating devices H02K29/06, H02K29/14
• CPC Class Codes: H02K 11/24 Devices for sensing torque, or actuated thereby H02K11/27 takes precedence
• CPC Class Codes: H02K 11/25 Devices for sensing temperature, or actuated thereby
• CPC Class Codes: H02K 11/35 Devices for recording or transmitting machine parameters, e.g. memory chips or radio transmitters for diagnosis
• CPC Class Codes: H02P 29/66 Controlling or determining the temperature of the rotor

Abstract

Disclosed herein is a shaft-mounted monitor for monitoring conditions of a rotating shaft using a calculated rotational component of the rotating shaft. The monitor may include a sensor such as an accelerometer, thermal sensor, strain gauge, or the like. In various embodiments, a variety of parameters relating to the rotating shaft may be monitored, such as a temperature, rotational speed, angular position, torque, power, frequency, or the like. The monitor may include a wireless transmitter to transmit the monitored condition of the rotating shaft to an intelligent electronic device or a monitoring system.

Claims

1. A shaft-mounted monitoring system configured to monitor a rotating shaft configured to transfer power from a prime mover to an electrical generator in an electric power generation system, the shaft-mounted monitoring system comprising:

a housing configured to be coupled to the rotating shaft;

a first sensor configured to be disposed within the housing, the first sensor further configured to output a first signal representative of a rotational component of the rotating shaft;

a second sensor configured to be disposed within the housing, the second sensor further configured to output a second signal representative of a second condition related to the rotating shaft, the second signal representing a physical condition different from a rotational component of the rotating shaft;

a processor in communication with the first sensor and the second sensor, and configured to;

calculate a first condition related to the rotational component based on the first signal; and

calculate a second condition based on the second signal, the second condition different from the rotational component of the rotating shaft;

a wireless transmitter in communication with the processor and configured to transmit a digitized representation of the first condition and the second condition to a consuming device; and

a power supply in electrical communication with the sensor, the wireless transmitter, and the processor, and configured to supply electrical power to the sensor, processor, and the wireless transmitter.

2. The shaft-mounted monitoring system of claim 1, wherein the consuming device comprises a protective relay configured to:

receive the digitized representation of the first condition and the second condition;

detect an anomalous condition based on the first signal; and

implement a protective action in response to the anomalous condition.

3. The shaft-mounted monitoring system of claim 2, wherein the anomalous condition comprises one of a locked rotor condition, an over-speed condition, and an under-speed condition.

4. The shaft-mounted monitoring system of claim 1, wherein the second sensor comprises a temperature sensor and the second condition comprises one of a temperature of the rotating shaft and an ambient temperature.

5. The shaft-mounted monitoring system of claim 1, wherein the second sensor comprises a strain sensor and the second condition comprises a torque on the rotating shaft.

6. The shaft-mounted monitoring system of claim 1, wherein the processor is further configured to generate a frequency domain representation of the first signal and to detect an anomalous vibration based on the frequency domain representation.

7. The shaft-mounted monitoring system of claim 6, wherein the processor is further configured to associate the anomalous vibration with an anomalous condition comprising one of a worn bearing, a broken bar, a shaft misalignment, and a load oscillation.

8. A shaft-mounted system configured to monitor a rotating shaft, the shaft-mounted system comprising:

a housing configured to be coupled to the rotating shaft;

a first sensor configured to be disposed within the housing, the first sensor further configured to output a first signal representative of a rotational component of the rotating shaft;

a strain sensor configured to be disposed within the housing and configured to output a second signal representative of a torque on the rotating shaft;

a processor in communication with the first sensor and the strain sensor, and configured to calculate a condition related to the rotational component based on the first signal and a torque of the rotating shaft based on the second signal;

a wireless transmitter in communication with the processor and configured to transmit a digitized representation of the calculated condition and the torque to a consuming device; and

a power supply in electrical communication with the first sensor and the strain sensor, the wireless transmitter, and the processor, and configured to supply electrical power to the first sensor, strain sensor, processor, and the wireless transmitter.

9. The shaft-mounted system of claim 8, wherein the first sensor comprises an accelerometer.

10. The shaft-mounted system of claim 9, wherein the condition comprises a rotational speed of the rotating shaft.

11. The shaft-mounted system of claim 9, wherein the condition comprises an angular position of the rotating shaft.

12. The shaft-mounted system of claim 9, wherein the accelerometer comprises at least a dual-axis accelerometer, and wherein one axis of the accelerometer is collinear with a radius of the rotating shaft.

13. The shaft-mounted system of claim 8, wherein the processor is further configured to determine a power transferred by rotating shaft based on the first condition and the torque.

14. The shaft-mounted system of claim 8, further comprising a filter configured to:

receive an output of the first sensor;

receive at least one criteria;

assert an alarm based on a deviation of the output from the criteria by at least a threshold amount.

15. The shaft-mounted system of claim 14, wherein the at least one criteria comprises a target frequency.

16. The shaft-mounted system of claim 15, wherein the filter is further configured to receive a time window and the alarm is asserted based on the deviation existing for a period exceeding the time window.

17. A shaft-mounted system configured to monitor a rotating shaft, the shaft-mounted system comprising:

a housing configured to be coupled to the rotating shaft;

a first sensor configured to be disposed within the housing, the first sensor further configured to output a first signal representative of a rotational component of the rotating shaft;

a second sensor configured to be disposed within the housing;

wherein the second sensor comprises a thermal sensor configured to output a second signal representative of a temperature of the rotating shaft;

a processor in communication with the first sensor and the second sensor and configured to calculate a condition related to the rotational component based on the first signal and a temperature of the rotating shaft based on the second signal;

a wireless transmitter in communication with the processor and configured to transmit a digitized representation of the calculated condition related to the rotational component and the temperature to a consuming device; and

a power supply in electrical communication with the first and second sensors, the wireless transmitter, and the processor, and configured to supply electrical power to the first and second sensors, processor, and the wireless transmitter.

18. The shaft-mounted system of claim 17, wherein the housing comprises a thermally conductive material and is in thermal communication with the shaft, and the second sensor is in thermal contact with the housing.

19. The shaft-mounted system of claim 17, further comprising a third sensor configured to determine an ambient temperature.

20. The shaft-mounted system of claim 17, further comprising a third sensor disposed along the length of the rotating shaft;

wherein the processor is further configured to extrapolate a temperature profile along the length of the rotating shaft based on temperature difference between the second sensor and the third sensor.